a) Field of the Invention
The present invention relates to a screwing control device of a computer chassis, and more particularly to a computer chassis, a panel surface of which is pre-built with a plurality of positioning holes, wherein a screw element with a central screw-hole can be optionally locked and positioned into one of the positioning holes which is at a proper position, so as to decrease a number of fixed bolts and to remove an obstacle which occurs upon installing components in the computer chassis, by screwing the screw element with other board element (such as a circuit board).
b) Description of the Prior Art
Referring to FIG. 7, a bottom panel E of a conventional computer chassis is riveted with a plurality of fixed bolts A, wherein a connection line A1 is used to represent that the bolt A is fixed and riveted with the panel E into one body; in other words, a center of the bolt A is provided with a female thread A2, such that the fixed bolt A can be screwed with a through-hole C1 in a circuit board C of a constant length and a constant width through a bolt B, in order to fix the circuit board C on the bottom panel E. However, a shortcoming is that the bottom panel E must be pre-punched with holes and then the bolts A are punched again to be riveted and fixed on the bottom panel E; therefore, the surface of the bottom panel E must be protruded and fixed with a lot of bolts A. When a number and positions of connection holes C1 of various sizes on the circuit board C are different; for example, if a new circuit board C of different size is to be installed on the bottom panel E, the excessive fixed bolts which are not used cannot be eliminated, which forms a new obstacle and prohibits these fixed bolts from being screwed and fixed with the connection holes C1 on the circuit board C. More particularly, in fact there are less than ⅔ of a total number of the projected fixed bolts that are actually used in a screwing condition, and the rest ⅓ are pre-built. Therefore, the unused bolts A may cause a huge waste.